Myxobacteria have a developmental cycle in which many cells aggregate to form a multicellular fruiting body. In order to move, swarm and fruit the cells communicate with each other. We propose to utilize the structural and genetic simplicity of these prokaryotic organisms to study the molecular basis of intercellular communication. In particular, we propose to isolate mutants defective in motility, in swarming and in fruiting. Then, by specific tests we have developed, we propose to identify those mutants altered in one or more channel of communication. Appropriate mutants will be investigated biochemically to identify the substances used for communication and genetically to identify the number of genes and how they are controlled.